The Design Of New Organic Dye, Synthesis And Applied Research In The Dye-sensitized Solar Cells

Dye-Sensitized Nano-crystalline Solar Cells (DSSC) are very prospective cleaning devices for the conversion of solar energy into electricity. In the past two decades, the performance of DSSC has been greatly improved. At present, the best performance devices, which have reached it maximum efficiency to 11.0-11.3%, are assembled by the ruthenium. However, ruthenium is very limited resource and has heavy metal toxicity, and metal-free organic dyes have the advantages of low cost, easy tailoring of molecular and high molar extinction coefficient. It has been received attention by various researchers in recent years and its highest efficiency has reached 9.8%.On the basis of a previous study on some donor-π-conjugated linker-acceptor (D-π-A) dyes, we have tried to identify that 2-ethylhexyloxy-substituted triphenylamine is a good donor in the construction of efficient organic sensitizers. We prepare several organic D-π-A dyes possessing differentπ-conjugated linkers. We have also studied the influence of heteroatoms on photocurrents and photovoltages with the aid of quantum calculations and transient photoelectrical decay measurements.we utilized a binaryπ-conjugated spacer of ethylenedioxythiophene and dithienosilole to construct a high molar absorption coefficient push-pull dye, characteristic of an intramolecular charge-transfer band peaking at 584 nm measured in chloroform. In comparison with the standard ruthenium sensitizer Z907, this metal-free chromophore C219 endowed a nanocrystalline titania film with an evident light-harvesting enhancement, leading to an unprecedented 10.0-10.3% efficiency at the AM1.5G conditions for dye-sensitized solar cells with non-ruthenium dyestuffs.We also utilized a binaryπ-conjugated spacer of ethylenedioxythiophene and dithiophene, Dithieno [3,2-b;2'3'-d] thiophene, 3,3-di-methy1-2, 2-bithiophene and 4,4'-dihexyl-4H-cyclopenta [2,1-b:3,4-b'] dithiophene,4a,5,6,7,8,8a-hexahydrobenzo [e] thieno [3,4-b] [1,4] dioxine and 3,3-di-n-hexylsilylene-2,2-bithiophene to construct a high molar absorption coefficient push-pull dye. We compare the route of synthesis and choice the best route in our works which have got the excellent results. Those achievement will considerably encourage further molecular and energy level engineering of low-cost metal-free organic dyes, boosting the practical application of dye-sensitized solar cells.